title: Growth hormone and cancer: an update on progress.
abstract: OBJECTIVE
  Animals born with a deficiency in the cell surface receptor for growth hormone (GH) have a significantly reduced risk of developing cancer. Conversely, increased expression levels of GH and the GH receptor (GHR) are detectable in a variety of different human cancers. Here we discuss recent literature contributing to our understanding of the field.
  
  
  RESULTS
  In addition to animal evidence, studies of individuals with Laron syndrome suggest that congenital GHR deficiency may also protect humans against cancer. GH expression in certain malignancies is correlated with clinicohistopathological parameters and may contribute the therapeutic resistance. Other recent studies have identified novel aspects of the GH signal transduction pathway, including receptor crosstalk and the involvement of microRNA in endocrine regulation of GH.
  
  
  CONCLUSIONS
  Substantial evidence suggests the GH/insulin-like growth factor-1 axis initiates and promotes progression of cancer. However, important questions remain unanswered regarding the therapeutic utility of GH or GHR antagonism in cancer. Further clinical studies regarding the clinical association of GH expression with human malignancies and translational studies investigating GHR antagonism in animal models of human cancer are critical.
authors.affiliation: Liggins Institute, University of Auckland, Auckland, New Zealand. j.perry@auckland.ac.nz
authors.forename: Jo K
authors.initials: JK
authors.lastname: Perry
authors.forename: Dong-Xu
authors.initials: DX
authors.lastname: Liu
authors.forename: Zheng-Sheng
authors.initials: ZS
authors.lastname: Wu
authors.forename: Tao
authors.initials: T
authors.lastname: Zhu
authors.forename: Peter E
authors.initials: PE
authors.lastname: Lobie
mesh_terms: D000818:Animals; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone